Process for preparing 2-butene-1,4-diol from dichlorobutenes

ABSTRACT

A process for preparing 2-butene-1,4-diol from dichlorobutenes which comprises hydrolyzing dichlorobutenes in the presence of water by using a water soluble formate of a metal selected from the group consisting of group Ia and IIa of the Periodic table. As a modification of the above mentioned process, an elemental metal selected from the group consisting of copper, iron and zinc or a compound thereof is further added to said reaction system as a catalyst thereby converting substantially all of mixture of isomeric dichlorobutenes into the desired 2-butene-1,4-diol.

United States Patent 1 Sakomura et a].

[73] Assignee: Toyo Soda Manufacturing Co., Ltd., Yamaguehi, Japan :2 Filed Nov. 1, 1972 211 Applr 1901302310 Related U.S. Application Data [63} Continuation of 581" No. 834,906, June I9, 1969,

abandoned.

l30| Foreign Application Priority Data June 24, 1968 Japan 43-43749 July 2. 1968 Japan 43-45568 |52| US. Cl 260/636; 260/637 R; 260/640;

[5|] Int. Cl. C07C 29/00 Field Of searchrm. 260/636, 640, 654 R, 654 H [56] References Cited UNITED STATES PATENTS 1221.667 4/1917 Brooks et al 260/640 123/076 8/l917 Mattenunw... 160/636 1,402,317 l/l922 Rodebush 260/636 2,042,223 5/1936 (Jroll et 260/654 R 2,299,477 10/1942 Hearnc et alv 260/654 H 2,323,781 7/1943 Kohler H 260/640 2,861,084 ll/l958 Starcher et al 260/654 H 2911.450 1 1/1959 weltonm. 260/654 R 3,060,237 10/1962 Bain 1 260/636 3,342,882 9/1967 Costain et a1. i v 260/654 R 3,349,129 10/1967 Stogryn et 260/636 Primary Examiner.loseph E, Evans Attorney, Agent, or Fl'rmFlynn 8-: Frishauf [57] ABSTRACT A process for preparing lbutene-IA-diol from dichlorobutenes which comprises hydrolyzing dichlorobutenes in the presence of water by using a water soluble Formate of a metal selected from the group consisting of group la and [in of the Periodic table. As a modification of the above mentioned pro cess, an elemental metal selected from the group consisting of copper, iron and zinc or a compound thereof is further added to said reaction system as a catalyst thereby converting substantially all of mixture of isomeric dichlorobutenes into the desired Z-butenedA- diol.

12 Claims, No Drawings PROCESS FOR PREPARING lBLTENE-lA-DIOL FROM [)IC H LOROBLTEN ES BACKGROUND OF THE INVENTION 1. Field of the Invention This is a continuation of application Ser. No. 834,906, filed June I), 1969 which has been abandoncd.

This invention relates to a process for preparing 2- butencl ,4 diol from dichlorobutencs using water soluble metal formate. In a modification of the process, copper, iron, zinc or a compound thereof is further added thereto. 2-butene-l .4-diol is known to be useful in the chemical industry. For example, this Z-butcnel,-1-diol can be converted into butane-1,4-diol, the raw material for production of polyester fiber and for production of tctrahydrofuran. a famous solvent. Also, it is useful as a raw material for production of 2,5- dihydrofuran, a widely used solvent and for polyacctal resin production.

2. Description of Prior Art It was known prior to this invention that an isomeric mixture of dichlorobutenes can be obtained in high yield by vapor phase chlorination of butadicne with elemental chlorine. The dichlorbutenes thus obtained are usually a mixture of 3,4 dichlorobutene and |,4- dichlorobutenc. The major of the mixture is usually |,4-isomer (a combination of cis-isomcr and transisomcrj, but the presence of 3,4-isomer cannot be neglected. And in fact. the ratio of 3,4-isomer to 1,4- isomer is about 0.5 or higher. In order to produce butenediol from such a mixture of dichlorobutencs, a hydrolyzing process using alkaline solution or water is usually adopted. The hydroxide, carbonate, bicarbonate. etc. of sodium, potassium, calcium, etc. are most often used as the alkali; however, these alkalis do not give a good yield. The primary reason for the low yield is probably due to the formation of polymer (probably polyethcr). When a hydroxide is employed, the formation of olefins such as monochlorobutadienc, etc. and the formation of cyclic ether and epoxide may constitute the main cause for such low yield; of course, the formation of such by-products varies depending upon the concentration of the hydroxide employed.

Further, it is natural that if hydrolyzing reaction is carried out by using such mixed dichlorobutcncs as the starting material, a mixture of 3-butene-l,2-diol and Z-butencl ,4-diol is formed. And even if, pure 3,4- dichlorol -butcne and l,4-dichloro-2-butcne is used as the starting material, a mixture of 3-butencl,2diol and Z-butencl .4-diol is produced. The reason for this is believed to be that since both of the dichlorobutcnes can be isomerized by allyl rearrangement reaction by each other, an isomerization reaction takes place in the course of the hydrolyzing reaction. Said isomerization is probably particularly significant, when hydroxide, carbonate. or bicarbonate of sodium. potassium or calcium, or water alone is used as the hydrolyzing agent.

The present inventors were searching for a way to improve yield and quality of product without off-setting disaduintages. It was found that 2-butene-l,4-diol can be prepared in high selectivity and in high yield by using an aqueous solution of a water soluble form-ate. for example formate of sodium, potassium, calcium and the like.

Incidentally, by the process of this invention, 3,4- dichloro-l-butcne is not subjected to hydrolysis and only l,4-dichlor2-butene is reacted in high selectivity and in high yield, and thereby Z-butenel ,4-diol is obtained almost quantitatively.

Further, in a modification of the process of this invention, a mixture of dichlorobutcnes can be completely converted into 2-butcne-l,4-diol selectively by adding an elemental metal selected from the group consisting of copper, iron and zinc or a compound thereof together with said formatc to the reaction system as the catalyst. The metal can be used in any form powder, ribbon, etc. As the compound, a compound such halide, formate, oxide, carbonate, and hydroxide can be used. Detailed conditions and processes for carrying out the present invention are given hereunder.

The composition of raw material dichlorobutcnes is not limited and a mixture of dichlorobutcnes having any composition can be used. However, when formate alone is used without the addition of copper, iron or zinc or a compound thereof, it is preferred to use a raw material which is rich in l,4-isomer since this gives a higher production rate per unit volume of the reactor.

Further, when consideration is also given to the product recovery operation, the steps required for carrying out the process of this invention can be simplified, if l,4-isomer is used as raw material. In case, copper, iron or zinc or a compound thereof is used in addition to the formate above mentioned, it is usually advantageous to use an isomeric mixture of dischlorobutcnes obtained by chlorination of butadicne.

The reaction velocity increases as the reaction temperature increases. When the reaction is carried out under atmospheric pressure, it is convenient to use the boiling temperature of the reaction mixture which, of course, depends on the concentration of formate used. Ifa higher temperature is used under an imposed pres sure, the reaction velocity increases as the temperature increases. However, a temperature higher than 150C is not suitable because it promotes side reactions, i.e. formation of high boiling materials. On the other hand, a temperature below 70C is not efficient because the reaction velocity is too low. Accordingly, the preferred range is within 70C to 150C.

It is desirable that the catalyst above mentioned be soluble in the reaction medium. However, a material which is, in general, referred to as insoluble can also be employed with good results. In general, the catalyst above mentioned is used in amount of from 0.0l to 10% by weight based on the raw material dichlorobutene. and when more than l07( by weight of catalyst is used, side reaction will increase, At the beginning of the reaction, said reaction is a heterogeneous one and therefore, strong agitation so as to provide a sufficient dispersion is desired.

The concentration of the aqueous solution of the formate can vary over a very wide range of from about 3wt9f to about 80wt7z Without accompanying any side reaction. It is to be noted that, as mentioned before, there is a limitation on the concentration of the aqueous solution of alkali; however, there is no strict limitation on the concentration of formate solution within the approximate range of 3-80 weight percent mentioned above.

Dichlorobutene can be added to the reaction mixture in one lot or incrementally. To insure maximum reaction velocity, thorough mixing is desired so the dichlorobutene will be thoroughly dispersed in said formate solution.

As the reaction proceeds, the dichlorobutcne phase disappears and only the water phase remains When a highly concentrated formate solution is employed. crystals of sodium chloride deposit in slurry form. Such deposition of sodium chloride slurry does not hinder the reaction.

The molar equivalent ratio of formate to dischlorobutene is not limited and can be selected freely. The unreacted dichlorobutene can be recovered almost completely. Therefore, an excess of dichlorobutene can he used without any loss. However, from the industrial view point, the use of excess formate is convenient. In general, it is preferred to keep the equivalent ratio of formate to dichlorobutene within a range of from 3.0:] to 0.8: I.

When l,4-dichloro-Z-butene is reacted with excess of formate, conversion goes up to almost l()()/(. The reaction mixture thus obtained comprises 2-butene'l ,4- diol. a small amount of ester of formic acid, a trace of 3-hutenel ,Z-diol. an excess of salt of formic acid, formic acid and metal chloride, the metal portion thereof corresponds to the metal portion of the salt added to the reaction system.

In summary, the characteristic features of this invention are that in a process for preparing 2-butene-l,4- diol from dichlorobutene, particularly from 1,4- dichloro-Z-butene, side reactions such as isomerization and polymerization can be avoided by the use of aque ous solution of formate, and, by the use of a slight excess of formate, the conversion of dichlorobutene goes up to lUUi. The latter feature makes the recovery op eration of butenediol very simple and easy.

In summary, the characteristic features of one of the modification ofthc invention i.e. a process modified by the additon of catalyst selected from the group consisting of copper, iron, zinc and the compound thereof, are as follows:

l. Dichlorobutanes entrained in the dichlorobutene starting material are not subjected to the reaction. Said dichlorobutanes consist mainly of compounds having adjoining carbon atoms, and each one thereof having a chlorine atom.

2. Conversion of dichlorobutene can he made almost lUUJ i by the use of a slight excess of formate.

3. All of the dichlorobutenes can be substantially Completely converted into Z-butenel ,4-diol in one step.

Advantages arising from the process in industrial application are as follows:

1. Dichlorohutanes which are difficult to separate from dichlorobutene reactants by distillation can be easily separated front said reactants by carrying out the reaction.

2. Any dichlorobutenes or mixture thereof can be used as the starting material.

3. Only 2-hutcne-l,4-diol can be formed from a mixture ofdichlorobutenes in high selectivity without using preisomerization.

4. Because only one step is required, the apparatus is simple.

Recovery of diol thus formed can be carried out by any process which is applicable to the recovery of water soluble material. However, it is advisable to carry out the recovery of diol after the addition of hydroxide, carbonate, bicarbonate, etc. in which the metal portion (ill thereof corresponds to the cation of the formate used. The amount of the salt to be added is the chemical equivalent amount calculated from the amount of dichlorobutenes reacted. By the addition of said salt, the formate can be reused repeatedly. Further, if the recovery of diol is carried out after the addition of said salt as above mentioned, it makes post-treatment easy and also it increases the yield of the product. The metal chlorides contained in the formate thus recovered do not hinder the reaction of this invention.

The following examples illustrate the invention.

EXAMPLE 1 [25g of l,4-dichloro-2-butene, 150g of sodium formate, and l25g of water were put in a one liter round bottom flask equipped with an agitator and reflux cooler. The mixture was agitated for 2 hours at a temperature of about 1 10C, i.e. the boiling point of the solution. Successively, 106g of sodium carbonate was added and heating and mixing were carried out for 20 minutes. The reaction mixture was then cooled to the room temperature; the crystals thus formed were washed with tetrahydrofuran and thereby the products were extracted. The extract was collected, and the tetrahydrofuran was distilled off. 855g of residuum was obtained. Successively. distillation was carried out under a reduced pressure of ISmmHg (abs) and 80.7g of distillate and 4.8g of residuum were obtained. Analysis of the distillate thus obtained by gaschromatography gave the following composition:

I-butcnel .4-diol 3butenel .Z-diol Conversion calculated from the formation of Cl was 99.3%. The yield of diol was 9l.7'/( taking into consideration the separation-purification operation.

EXAMPLE 2 g of l,4-dichloro-2-butene, g of sodium formate, and 450g of water were put in a one liter round bottom flask equipped with an agitator and reflux cooler. The mixture was agitated for 2 hours at a temperature of about 103C, i.e. the boiling temperature of the solution. The conversion calculated from the formation of Cl was 99.7%. Successively, l06g of sodium carbonate was added to the mixture and heating and mixing were carried out for 20 minutes. Then, water was distilled off in a rotary evaporator. The crystals thus obtained were washed with acetone; thereby the product was extracted. The extract was collected and acetone was distilled ofi. 86g of residum was obtained. Analysis by gas-chromatography gave the following composmon:

The yield of l,4-diol at this stage was 95.7% and the yield of l,2-diol was 0.9871. successively, distillation was carried out under a reduced pressure of l5mml-lg and 8 l .5g of distillate was obtained. The composition of the distillate was almost the same as that of the feed for the distillation operation. Rate of recovery in this distillation step was 94.7% by weight. Over all yield of diol was 92.6% taking into consideration of said recovery operation.

EXAMPLE 3 125g of l 4dichloro-Z-butene. 63g of 3.4-dichlorol-butcne. ISUg of sodium formate and 450g of water were put in the same apparatus as in Example l and Z. The mixture was heated and agitated for 2 hours at 96C. Then the reflux cooler was replaced with a simple distillation column. Dichlorobutcnes, water and formic acid were distilled out at a reflux ratio of lzl.

Still bottom liquor was. after the addition of about 30g of sodium carbonate. boiled for about minutes under refluxing. and then dried out in a rotary evaporator. The residuum was then extracted with acetone.

From the extract. acetone was distilled off and 84g of residuum A was obtained. The distillate was neutralized with sodium bicarbonate. and then separated oily portion was collected. 62g of material B was collected.

Analysis of residuum (A) by gas-chromatography showed the following result:

Z-butencl -l-tliol )8 wtii f -hutencl Idiol I wt'w? Yield of Z-butenel .4-diol calculated from L4- dichloro-Z-butene corresponded to 93%.

Analysis of oil material (B) by gas chromatography gave the following results:

BA-tlichloro-l-hutene 19 1";

Recor ery rate calculated from 3.5dichloro-l-butcne used as the starting material corresponded to 97.5%. Example 4.

lXSg of potassium formate. 70g of water were put in a one liter round bottom flask equipped with an agitator and a reflux cooler. and the contents of the flask was warmed and dissolved. Then lg of 1.4-dichloro- Z-butene was added to the flask and the reaction was carried out for 3 hours under agitation at l 15C. Then aqueous solution of potassium hydroxide having a concentration of 20% by weight was added to the reaction mixture to neutralize the the reaction mixture until the pH thereof went up to 10. After drying out the reaction mixture. the product was extracted from the crystal with tetrahydrofumn. When the extracting agent was distilled off. 892g of the residuum was obtained. Analysis of the residuum by gas-chromatography gave the following result:

The yield of lbutcne-lA-diol corresponded to 91%.

EXAMPLE 5 tinder the same conditions and using the same apparatus and the same amount of raw material as in Example 4. reaction was carried out except that 150g of calcium form-ate was used in lieu of potassium formate. After 3 hous reaction. the oily phase disappeared. Then. the reaction mixture was flCttIfllllI Cd with calcium carbonate powder and further saturated with potassium chloride. The reaction mixture was subjected to liquid-liquid extraction by using tetrahydrofuran. The extract contained 695g of 2-butenc-l.4-diol and (155g of B-butene-LZ-diol. The yield of said l.-l-diol was 79'? and said l.Z-diol was 1.8%.

EXAMPLE 6 The same apparatus as used in Example I was used. 408g of sodium formate and 324g of water were put in the apparatus and the contents of the flask was warmed and dissolved. Then 125g of l.4-dichloro2-butene was added to the flask and the reaction was carried out for 2 hours under agitation at 110C. "[lien. in order to neutralize the reaction mixture. aqueous solution of so dium hydroxide having a concentration of 47)? by weight was added to the reaction mixture until the pH there of went up to 9. After drying out the reaction mixture, the product was extracted from the crystal with tetrahydrofuran. When the extracting agent was distilled off. 96.4g of residuum was obtained. Analysis of the residuum by gas-chromatography gave the following result:

Z-butenel .4-diol 3-butencl .2-diol The yield of 2-butene-l.4-diol corresponded to 93.7%.

EXAMPLE 7 [25g of mixed dichlorobutenes (42g of 3.4-dichloro l-butene, 83g of cisand trans-l.4-dichloro-lbutene 150g of sodium formatc. 450g of water and 5g of basic copper carbonate were put in a one liter round bottom glass flask equipped with an agitator and a reflux cooler. The mixture was agitated for 2 hours at a tem perature of about 100C. Then 106g of sodium carhonate was added thereto and agitation was carried out for an additional 20 minutes. The content was dried out in a rotary evaporator. and about 40 1 ml of water was obtained. At the distillate receiver bottom. ().5g of oily material was found. Analysis of the oily material by gaschromatography showed 3.4- and 1.4-dichlorohutene.

The crystals thus obtained were washed and extracted with tetrahydrofuran.. and then tetrahydrofuran was distilled off from the extract; thereby g of residuum was obtained. The result of analysis was follows:

The yield of 2-butene-l.4-diol calculated from mixed dichlorobutcnes was 9171. Comparative Example 1.

125g of 3.4-dichloro-l-butene, lSUg of sodium formate and 450g of water were added to the same apparatus as in EXample 7. The mixture was agitated for 6 hours at a temperature of about -97C. The dichlorobutene phase. existing as an oily state floated on the upper portion of the reaction mixture. The conver sion of dichlorobutene calculated from the amount of Cl formation was only 6%.

EXAMPLE 8 After the reaction of Comparative Example I. 5g of copper formate was added to the reaction mixture and agitation was carried out for 2.5 hours at a temperature of 97lt)3C'. Then lOog of sodium carbonate was added thereto and agitation was carried out for an additional 20 minutes at the same temperature. The content was distilled off. in the distilled water. there was absolutely no oily material. The crystals thus obtained were extracted sexeral times with tetrahydrofuran and the extracting agent was distilled off Thus. 84g of residuum was obtained. The result of the analysis was as follows.

The yield of Z-butene-l.4-diol was 90%.

EXAMPLE 9 |Zg of mixed dichlorobutcnes (3,4-isomer 42g, [,4- isomer 83g). 200g of sodium formate 500g of water and 5g of cupric chloride were put in a 2 liter round bottom flask equipped with a reflux cooler and a mixer. The mixture was mixed for 2 hours at a temperature of about 100C Then l()6g of sodium carbonate was added and agitation was carried out for an additional l5 minutes.

Successively. 125g of mixed dichlorobutenes (the composition of which was identical to that mentioned above) was added to the mixture and agitated for 2 hours and 106g of sodium carbonate was further added thereto and mixing was carried out for minutes. This procedure was repeated once again. The contents of the flask was dried out in a rotary evaporator and the residuum was extracted with tetrahydrofuran. After the extracting agent was distilled off, 252g of residuum was obtained. The composition of the residuum was 2- butcnel,4-diol 9Z9 3-butene-LZ-diol 2% and the other components 6% (7r is expressed in term of by weight. respectively]. The yield of Z-butene-lA-diol calculated from the mixed diehlorobutenes used was 88%. After drying out. the weight of the crystals was 55lg. The composition thereof was as follows:

sodium chloride 350g sodium forinatc copper (calculated as cupric chloride) 38g The comersion of mixed dichlorobutenes corresponded to 99.7%.

COMPARATlVE EXAMPLE 2 Using the sanieapparatus as in Example 7, the same amounts of materials was put in the apparatus as in Ex* ample 7 and then ltlg of LZ-dichlorobutane and g of 2.3-dichlorobutane were added thereto. Agitation of the reaction mixture was carried out for the same length of time at the same temperature as in Example 7. Then. the reaction was carried out for the same length of time using the same amount of sodium carbonate as in Example 7 and then lOOg of water was added to the reaction mixture. After the addition of water, the reaction mixture was dried out in a rotary evaporator. The distilled water fraction obtained by the evaporation step contained 19g of oily material at the bottom thereof. The composition analysis of the oily portion by gas-chroniatography gave the following result:

l.I-dichlorobutanc I.ldichlorobutanc total of l-l-dichlorw l butenc and iA-dichloro-Z-butcne l wt r results of analysis The yield of Z-butene-lA-diol was 82%.

EXAMPLE I 1 Under the same conditions and using mixed dichlorobutenes having same composition and using the same apparatus as used in Example 7, reaction was car ricd out except that 3g of copper powder was added instead of basic copper carbonate. After the reaction had been completed, post-treatments were carried out simi larly. After tetrahydrofuran extractant was distilled off, 89g of residuum was obtained.

result of analysis The yield of 2 butene l.4-diol was 79%.

EXAMPLE 12 Under the same conditions and using the same apparatus and raw materials as in Example 7, reaction was carried out except that 5g of zinc oxide was added instead of basic copper carbonate. After the reaction had been completed, post-treatments were carried out similarly. After tctrahydrofuran extractant was distilled Off. 8 lg of residuum was obtained.

result of analysis The yield of Z-butene- 1,4-diol was 6572.

EXAMPLE 13 Under the same conditions and using the same apparatus and raw materials in Example 7. reaction was carried out except that 5g of ferric hydroxide was added instead of basic copper carbonate. After the reaction had been completcd, post-treatments were carried out similarly. After tetrahydrofuran extractant was distilled off, 89g of residuum was obtained.

result ol analysis The yield of 2-butenel ,4-diol was 8091'.

EXAMPLE 14 result ol analysis The yield of 2-butene-l.4-diol was 66%.

EXAMPLE 15 Under the same conditions and using the same apparatus and raw materials as in Example 7. reaction was carried out except that g of cupric hydroxide was added instead of basic copper carbonate. After the reaction had been completed. post-treatments were car ried out similarly. After tetrahydrofuran extraetant was distilled off. 85g of residuum was obtained.

result ol analysis Z-l utenel .J-diol 74 wt) 3-bulene-l .2-Llltll l1 \tt'i others l4 at) The yield of Z-butenel .4-diol was7 l /l.

EXAMPLE l6 Under the same conditions and using the same apparatus and raw materials as in Example 7. reaction was carried out except that 5g of iron powder was added instead of basic copper carbonate. After the reaction had been completed. post-treatments were carried out simi larly. After the tetrahydrofuran extractant was distilled off. 86g of residuum was obtained.

result of analysis I-butcnel .J tllUl -butcnu l .I'tliol others The yiled of I-butenel .4-diol was 78%.

EXAlVlPLE l7 Lnder the same conditions and using the same apparatus and ran materials as in Example 7. reaction was carried out except that 5g of zinc powder was added instead of basic copper carbonate. After the reaction had result of analysis The yield of 2-butene-l.4-diol was 67%.

EXAMPLE 18 Same apparatus as used in Example 7 was used. 408g of sodium formate. 324g of water and lg of copper formate were put in the apparatus and the contents of the flask was warmed and dissolved. Then. lg of mixed dichlorobutenes having the same composition as used in Example 7 was added to the flask and the reaction was carried out for 2 hours under agitation at l 10C Then. in order to neutralize the reaction mixture, aque ous solution of sodium hydroxide having a concentration of 47% by weight was added to the reaction mixture. until the pH thereof went to 9. After drying out the reaction mixture. the product was extracted from the crystal with tetrahydrofuran. When the extracting agent was distilled off. 96.0g of residuum was obtained. Analysis of the residuum by gas-chromatography gave the following result:

Zhutenel .Jaliul 3-hutene l .Zaliol The yield of Z-butenel .4-diol corresponded to 92.5%.

What is claimed is:

l. A process for preparing 2-butene-l,4diol from l.4-dichloro-2-butcnc or a mixture of dichlorobutenes rich in 1.4-dichloro-2-butene by a hydrolysis reaction comprising hydrolyzing L Ldichloro-Z-butene in a reaction charge of (I) said l,4-dichloro-2-butene. (2) water and (3) a water soluble formate of a metal selected from the group consisting of metals of la and group Ila of the periodic table at a temperature of from C. to I50C.. the concentration of the aqueous solution of said formate being from about 3 to about percent by weight and the equivalent ratio of said formate to said dichlorobutene being within a range from about 3:1 to about 0.8:].

2. A process of claim I, wherein the starting material employed is 1,4-dichloro-2-butene.

3. A process of claim 1, wherein said mixture of dichlorobutenes is obtained from vapor phase chlorination of butadiene.

4. A process of claim 1, wherein said formate is selected from the group consisting of sodium formate. potassium formate and calcium formate.

5. A process of claim 1. wherein a hydroxide. carbonate or bicarbonate of the metal corresponding to the cation of said formate is added to the resulting reaction mixture. the amount of said hydroxide. carbonate or bicarbonate being chemically eqivalent to the amount of said dichlorobutene.

6. A process for preparing Z-butenel .4-diol from a mixture of dichlorobutenes by a hydrolysis reaction comprising hydrolying a reaction charge of( I a mixture ofdiehlorobutcncs (I) water, (3) a water soluble form-ate of a metal selected from the group consisting of metals of group la and group lla of the periodic table, and (4 a member selected from the group consist ing of copper, iron, zinc. and a halide, oxide, hydroxide, carbonate or lower aliphatic acid salt thereof as a catalyst. at a temperature of from 70C. to lSUC., the concentration of the aqueous solution of said form-ate being in a range of from about 3 to about 80 percent by weight and the molar ratio of said formate to said di chlorobutene being within a range of from about 3:1 to about 0.811, whereby substantially all of said dichlorobutenes are converted into Z-butene-lA-diol.

7. A process ofclaim 6, wherein the amount of catalyst employed is within a range oftHH l); by weight based on dichlorobutenes employed.

8. A process of claim 6, wherein said formate is selected from the group consisting of sodium formate,

potassium formate and calcium formatei 9. A process of claim 6, wherein said catalyst is selected from the group consisting of halide. oxide, by droxidc, carbonate and lower aliphatic acid salt of copper. iron and zinc,

I0. A process of claim 6, wherein said catalyst is selected from the group consisting of copper formate and copper chloride 1 l. A process of claim 6, wherein said mixture of di chlorobutenes is obtained from vapor phase chlorination of butadiene.

12. A process of claim 6, wherein a hydroxide, carbonate or bicarbonate of the metal corresponding to the cation of said formate is added to the resulting reaction mixture, the amount of said hydroxide, carbonate or bicarbonate being chemically equivalent to the amount of said diehlorobutene. 

1. A PROCESS FOR PREPARING 2-BUTENE-1,4-DIOL FROM 1,4DICHLORO-2-BUTENE OR A MIXTURE OF DICHLOROBUTENES RICH IN 1,4-DICHOLRO-2-BUTENE IN A REACTION CHARGE OF (1) HYDROLYZING 1,4-DICHLORO-2-BUTENE IN A REACTION CHARGE OF (1) SAID 1,4-DICHOLRO-2-BUTENE, (2) WATER AND (3) A WATER SOLUBLE FORMATE OF A METAL SELECTED FROM THE GROUP CONSISTING OF METALS OF 1A AND GROUP 11A OF THE PERIODIC TABLE AT A TEMPERATURE OF FROM 70*C, TO 150*C., THE CONCENTRATION OF THE AQUEOUS SOLUTION OF SAID FORMATE BEING FROM ABOUT 3 TO ABOUT 80 PERCENT BY WEIGHT AND THE EQUIVALENT RATIO OF SAID FORMULAE TO SVAID DICHLOROBUTENE BEING WITHIN A RANGE FROM ABOUT 3:1 TO ABOUT 0.8:1.
 2. A process of claim 1, wherein the starting material employed is 1,4-dichloro-2-butene.
 3. A process of claim 1, wherein said mixture of dichlorobutenes is obtained from vapor phase chlorination of butadiene.
 4. A process of claim 1, wherein said formate is selected from the group consisting of sodium formate, potassium formate and calcium formate.
 5. A process of claim 1, wherein a hydroxide, carbonate or bicarbonate of the metal corresponding to the cation of said formate is added to the resulting reaction mixture, the amount of said hydroxide, carbonate or bicarbonate being chemically eqivalent to the amount of said dichlorobutene.
 6. A process for preparing 2-butene-1,4-diol from a mixture of dichlorobutenes by a hydrolysis reaction comprising hydrolyzing a reaction charge of (1) a mixture of dichlorobutenes, (2) water, (3) a water soluble formate of a metal selected from the group consisting of metals of group Ia and group IIa of the periodic table, and (4) a member selected from the group consisting of copper, iron, zinc, and a halide, oxide, hydroxide, carbonate or lower aliphatic acid salt thereof as a catalyst, at a temperature of from 70*C. to 150*C., the concentration of the aqueous solution of said formate being in a range of from about 3 to about 80 percent by weight and the molar ratio of said formate to said dichlorobutene being within a range of from about 3:1 to about 0.8:1, whereby substantially all of said dichlorobutenes are converted into 2-butene-1,4-diol.
 7. A process of claim 6, wherein the amount of catalyst employed is within a range of 0.01 - 10% by weight based on dichlorobutenes employed.
 8. A process of claim 6, wherein said formate is selected from the group consisting of sodium formate, potassium formate and calcium formate.
 9. A process of claim 6, wherein said catalyst is selected from the group consisting of halide, oxide, hydroxide, carbonate and lower aliphatic acid salt of copper, iron and zinc.
 10. A process of claim 6, wherein said catalyst is selected from the group consisting of copper formate and copper chloride.
 11. A process of claim 6, wherein said mixture of dichlorobutenes is obtained from vapor phase chlorination of butadiene.
 12. A process of claim 6, wherein a hydroxide, carbonate or bicarbonate of the metal corresponding to the cation of said formate is added to the resulting reaction mixture, the amount of said hydroxide, carbonate or bicarbonate being chemically equivalent to the amount of said dichlorobutene. 